Last July, the Obama Administration sued the state of Arizona over its immigration law. Yesterday, Arizona Gov. Jan Brewer counter-sued, claiming that the federal government had failed to protect the Arizona-Mexico border and that an “invasion” of illegal immigrants was threatening the state.

Gov. Brewer’s counter-suit puts the immigration issue squarely in the middle of next year’s US Senate election in Arizona, which was thrown open yesterday by the retirement of veteran Sen. John Kyl.

“The first and foremost issue we’re facing right now is the security, safety and welfare of our citizens,” Brewer said at a press conference outside Phoenix’s federal courthouse. “The federal government needs to step up and do their job.”

The state “did not ask for this fight with the federal government,” she said, “but now that we are in it, Arizona will not rest until our border is secured and federal immigration laws are enforced.”

Arizona’s filings allege that the federal government failed to maintain “operational control” of the border, protect the state from “an invasion” of illegal immigrants, enforce immigration laws and abide by the 10th Amendment to the U.S. Constitution, which gives states and the people powers not explicitly granted to the federal government.

“The federal government has effectively conceded its inability to protect Arizona and its citizens from criminal activities associated with illegal aliens,” the state said in its filing.”Within the last year, the federal government placed warning signs in the desert 80 miles north of the border and only 30 miles south of Phoenix warning people to stay away from the area.”